[PATCH v4 08/11] block/io: allow 64bit write-zeroes requests - Vladimir Sementsov-Ogievskiy

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, integration@gluster.org,
	namei.unix@gmail.com, dillaman@redhat.com, berto@igalia.com,
	eblake@redhat.com, pl@kamp.de, ronniesahlberg@gmail.com,
	fam@euphon.net, sw@weilnetz.de, stefanha@redhat.com,
	pbonzini@redhat.com, pavel.dovgaluk@ispras.ru, ari@tuxera.com,
	mreitz@redhat.com, kwolf@redhat.com, vsementsov@virtuozzo.com,
	jsnow@redhat.com
Subject: [PATCH v4 08/11] block/io: allow 64bit write-zeroes requests
Date: Wed, 24 Mar 2021 23:51:29 +0300	[thread overview]
Message-ID: <20210324205132.464899-9-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20210324205132.464899-1-vsementsov@virtuozzo.com>

Now, when all drivers are updated by previous commit, we can drop two
last limiters on write-zeroes path: INT_MAX in
bdrv_co_do_pwrite_zeroes() and bdrv_check_request32() in
bdrv_co_pwritev_part().

Now everything is prepared for implementing incredibly cool and fast
big-write-zeroes in NBD and qcow2. And any other driver which wants it
of course.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/io.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/block/io.c b/block/io.c
index 79e600af27..a3c2b7740c 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1836,7 +1836,8 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
     int head = 0;
     int tail = 0;
 
-    int64_t max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, INT_MAX);
+    int64_t max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes,
+                                            INT64_MAX);
     int alignment = MAX(bs->bl.pwrite_zeroes_alignment,
                         bs->bl.request_alignment);
     int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, MAX_BOUNCE_BUFFER);
@@ -2212,7 +2213,11 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
         return -ENOMEDIUM;
     }
 
-    ret = bdrv_check_request32(offset, bytes, qiov, qiov_offset);
+    if (flags & BDRV_REQ_ZERO_WRITE) {
+        ret = bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, NULL);
+    } else {
+        ret = bdrv_check_request32(offset, bytes, qiov, qiov_offset);
+    }
     if (ret < 0) {
         return ret;
     }
-- 
2.29.2


